This invention relates to a fabric for power transmission belt for reinforcing a power transmission belt and a power transmission belt using the same.
In general, a power transmission belt such as a V-belt and a v-ribbed belt transmits power by using a frictional force to pulleys and such a friction exerts a static electricity. A synchronous belt also involves a friction at the time of engagement with pulleys thereby producing a static electricity similarly. When such a static electricity is charged to the power transmission belt, pulleys and the like, the belt may be damaged or peripheral electric equipment may be broken down. Therefore, it has been required to make the power transmission belt conductive thereby preventing the power transmission belt from becoming electrostatically charged.
As a technique to meet the requirement, there is known a conventional technique of imparting electric conductivity to a power transmission belt in such a manner as to add a conductive material such as carbon and zinc powder to rubber cement which is used in a treatment to a fabric for belt to be adhered to the surface of a belt body.
In the above conventional technique, however, it is necessary to secure the electric conductivity of the belt surface over a specific level. Therefore, an amount of rubber cement used for the fabric for belt must be increased more than commonly used so that a rubber cement layer having a specific thickness is formed on the fabric surface which is to form the belt surface. As a result, when the transmission belt to which the fabric is adhered is used, the rubber cement is worn out or agglomerated due to friction to pulleys thereby readily forming a level difference on the fabric surface. This may produce a beating sound.
Further, in view of the need for maintaining the adhesive property or the like between the belt body and the fabric, an amount of carbon to be mixed into the rubber cement is limited. Accordingly, extensive improvement in electric conductivity cannot be expected and therefore an effect of successfully preventing electrostatic charge cannot be implemented.
Furthermore, since worn-out dusts of the rubber cement are produced, the power transmission belt cannot be used for applications averse to particulates such as applications involving foods.
An object of the present invention is to improve a method for making a power transmission belt conductive thereby preventing production of beating sound and production of worn-out dusts in using the power transmission belt and to further enhance the electric conductivity of a power transmission belt thereby successfully preventing electrostatic charge of the belt.